Association of Duddingtonia flagrans with microorganisms for management of Meloidogyne javanica and acquisition of nutrients in soybean

•Epiphytic association of D. flagrans in soybean roots controls M. javanica.•Compatible association between D. flagrans and P. chlamydosporia for management of root-knot nematodes.•D. flagrans can be co-inoculated with N-fixing bacteria in soybean plants to promote nutrient acquisition. The use of beneficial microorganisms in agricultural production systems has been growing due to the worldwide demand for more sustainable crops. Biological control has thus gained prominence in the management of plant parasitic nematodes, as the result of the efficiency in reducing their population densities, improving plant development. The objectives of this study were to evaluate the association of the nematophagous fungi Duddingtonia flagrans and Pochonia chlamydosporia to reduce the population of Meloidogyne javanica in soybean, and to check if D. flagrans promotes the acquisition of nutrients in soybean. The plant-parasitic nematode biocontrol experiment was carried out twice, at 20 and 27 °C. In the nutrient acquisition test, plants grown in soil infested by D. flagrans and/or Bradyrhizobium japonicum were compared with plants grown in soil without the application of these organisms. All treatments with fungi resulted in reductions in the numbers of eggs and galls per g of root, when compared to the control. A compatible association between D. flagrans and P. chlamydosporia was verified in the experiment. For the nutrition test, the fungus, combined or not with B. japonicum, promoted an increase in the nutrient content in the soybean roots. In this study, we found that D. flagrans may be associated with other microorganisms to control nematodes and to promote the acquisition of nutrients.